Re-add btree_gist description.
Re-add btree_gist description.

yuanzhao/gpdb,tpostgres-projects/tPostgres,kaknikhil/gpdb,cjcjameson/gpdb,ahachete/gpdb,randomtask1155/gpdb,lintzc/gpdb,lisakowen/gpdb,chrishajas/gpdb,cjcjameson/gpdb,ovr/postgres-xl,arcivanov/postgres-xl,atris/gpdb,lpetrov-pivotal/gpdb,rubikloud/gpdb,postmind-net/postgres-xl,tangp3/gpdb,yuanzhao/gpdb,janebeckman/gpdb,Chibin/gpdb,ashwinstar/gpdb,ovr/postgres-xl,lintzc/gpdb,janebeckman/gpdb,royc1/gpdb,edespino/gpdb,ahachete/gpdb,techdragon/Postgres-XL,randomtask1155/gpdb,randomtask1155/gpdb,xuegang/gpdb,zaksoup/gpdb,greenplum-db/gpdb,edespino/gpdb,Quikling/gpdb,ashwinstar/gpdb,lpetrov-pivotal/gpdb,50wu/gpdb,Quikling/gpdb,kaknikhil/gpdb,lintzc/gpdb,greenplum-db/gpdb,yazun/postgres-xl,chrishajas/gpdb,greenplum-db/gpdb,tangp3/gpdb,greenplum-db/gpdb,50wu/gpdb,lintzc/gpdb,jmcatamney/gpdb,snaga/postgres-xl,greenplum-db/gpdb,Quikling/gpdb,CraigHarris/gpdb,Chibin/gpdb,rvs/gpdb,50wu/gpdb,Chibin/gpdb,0x0FFF/gpdb,tangp3/gpdb,cjcjameson/gpdb,foyzur/gpdb,jmcatamney/gpdb,edespino/gpdb,Chibin/gpdb,zaksoup/gpdb,randomtask1155/gpdb,arcivanov/postgres-xl,techdragon/Postgres-XL,xinzweb/gpdb,0x0FFF/gpdb,Quikling/gpdb,Quikling/gpdb,rvs/gpdb,edespino/gpdb,edespino/gpdb,techdragon/Postgres-XL,rvs/gpdb,CraigHarris/gpdb,rubikloud/gpdb,lpetrov-pivotal/gpdb,rubikloud/gpdb,CraigHarris/gpdb,zaksoup/gpdb,pavanvd/postgres-xl,adam8157/gpdb,oberstet/postgres-xl,foyzur/gpdb,ashwinstar/gpdb,lisakowen/gpdb,0x0FFF/gpdb,lintzc/gpdb,rvs/gpdb,lisakowen/gpdb,kaknikhil/gpdb,jmcatamney/gpdb,atris/gpdb,rvs/gpdb,chrishajas/gpdb,foyzur/gpdb,kaknikhil/gpdb,Chibin/gpdb,lpetrov-pivotal/gpdb,tangp3/gpdb,randomtask1155/gpdb,atris/gpdb,ovr/postgres-xl,xinzweb/gpdb,rvs/gpdb,rubikloud/gpdb,arcivanov/postgres-xl,chrishajas/gpdb,royc1/gpdb,kaknikhil/gpdb,xuegang/gpdb,xinzweb/gpdb,Postgres-XL/Postgres-XL,royc1/gpdb,jmcatamney/gpdb,janebeckman/gpdb,zeroae/postgres-xl,Chibin/gpdb,0x0FFF/gpdb,rubikloud/gpdb,atris/gpdb,rvs/gpdb,rvs/gpdb,kmjungersen/PostgresXL,janebeckman/gpdb,edespino/gpdb,lintzc/gpdb,Quikling/gpdb,yazun/postgres-xl,ahachete/gpdb,xinzweb/gpdb,greenplum-db/gpdb,ovr/postgres-xl,Quikling/gpdb,ahachete/gpdb,pavanvd/postgres-xl,cjcjameson/gpdb,oberstet/postgres-xl,ovr/postgres-xl,jmcatamney/gpdb,ahachete/gpdb,Chibin/gpdb,jmcatamney/gpdb,adam8157/gpdb,janebeckman/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,adam8157/gpdb,postmind-net/postgres-xl,chrishajas/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,50wu/gpdb,rvs/gpdb,cjcjameson/gpdb,tpostgres-projects/tPostgres,lisakowen/gpdb,yuanzhao/gpdb,arcivanov/postgres-xl,ashwinstar/gpdb,oberstet/postgres-xl,snaga/postgres-xl,greenplum-db/gpdb,royc1/gpdb,ashwinstar/gpdb,chrishajas/gpdb,pavanvd/postgres-xl,xuegang/gpdb,50wu/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,zaksoup/gpdb,foyzur/gpdb,kmjungersen/PostgresXL,Quikling/gpdb,foyzur/gpdb,cjcjameson/gpdb,rubikloud/gpdb,xuegang/gpdb,50wu/gpdb,randomtask1155/gpdb,ashwinstar/gpdb,rubikloud/gpdb,xinzweb/gpdb,zaksoup/gpdb,xuegang/gpdb,zaksoup/gpdb,Chibin/gpdb,royc1/gpdb,chrishajas/gpdb,lpetrov-pivotal/gpdb,0x0FFF/gpdb,ahachete/gpdb,Chibin/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,xinzweb/gpdb,snaga/postgres-xl,atris/gpdb,janebeckman/gpdb,lisakowen/gpdb,yazun/postgres-xl,lintzc/gpdb,cjcjameson/gpdb,tangp3/gpdb,Postgres-XL/Postgres-XL,techdragon/Postgres-XL,kmjungersen/PostgresXL,xinzweb/gpdb,tangp3/gpdb,foyzur/gpdb,Postgres-XL/Postgres-XL,snaga/postgres-xl,edespino/gpdb,tangp3/gpdb,yuanzhao/gpdb,rubikloud/gpdb,Postgres-XL/Postgres-XL,chrishajas/gpdb,adam8157/gpdb,royc1/gpdb,postmind-net/postgres-xl,tpostgres-projects/tPostgres,cjcjameson/gpdb,lpetrov-pivotal/gpdb,CraigHarris/gpdb,zeroae/postgres-xl,lintzc/gpdb,atris/gpdb,ahachete/gpdb,edespino/gpdb,kaknikhil/gpdb,postmind-net/postgres-xl,rvs/gpdb,Chibin/gpdb,zeroae/postgres-xl,tangp3/gpdb,royc1/gpdb,janebeckman/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,pavanvd/postgres-xl,cjcjameson/gpdb,50wu/gpdb,arcivanov/postgres-xl,snaga/postgres-xl,yazun/postgres-xl,CraigHarris/gpdb,lisakowen/gpdb,tpostgres-projects/tPostgres,zaksoup/gpdb,adam8157/gpdb,zeroae/postgres-xl,yuanzhao/gpdb,royc1/gpdb,lintzc/gpdb,kaknikhil/gpdb,foyzur/gpdb,yazun/postgres-xl,adam8157/gpdb,janebeckman/gpdb,greenplum-db/gpdb,xinzweb/gpdb,oberstet/postgres-xl,kmjungersen/PostgresXL,adam8157/gpdb,kmjungersen/PostgresXL,atris/gpdb,kaknikhil/gpdb,Postgres-XL/Postgres-XL,50wu/gpdb,ahachete/gpdb,yuanzhao/gpdb,zaksoup/gpdb,janebeckman/gpdb,CraigHarris/gpdb,jmcatamney/gpdb,lpetrov-pivotal/gpdb,Quikling/gpdb,pavanvd/postgres-xl,randomtask1155/gpdb,kaknikhil/gpdb,xuegang/gpdb,cjcjameson/gpdb,ashwinstar/gpdb,adam8157/gpdb,xuegang/gpdb,foyzur/gpdb,lpetrov-pivotal/gpdb,0x0FFF/gpdb,postmind-net/postgres-xl,0x0FFF/gpdb,edespino/gpdb,tpostgres-projects/tPostgres,Quikling/gpdb,janebeckman/gpdb,xuegang/gpdb,edespino/gpdb,lisakowen/gpdb,CraigHarris/gpdb,CraigHarris/gpdb,0x0FFF/gpdb,arcivanov/postgres-xl,atris/gpdb,xuegang/gpdb,randomtask1155/gpdb,lisakowen/gpdb